Electrosurgical cutting and sealing instruments with cam-actuated jaws

ABSTRACT

Various embodiments are directed to a surgical instrument comprising, a shaft, and an end effector. The shaft may be coupled to the handle and may extend distally along an longitudinal axis. The end effector may be positioned at a distal end of the shaft and may comprise first and second jaw members, a reciprocating member, a shuttle and at least one cam pin. The first and second jaw members may define first and second longitudinal slots and first and second cam slots and may be pivotable towards one another about a pivot point. The reciprocating member may be translatable distally and proximally parallel to the longitudinal axis and through the first and second longitudinal slots. A distal portion of the reciprocating member may define a blade. The shuttle may be translatable distally and proximally parallel to the longitudinal axis. The cam pin may be coupled to the shuttle and positioned within the first cam slot and the second cam slots.

BACKGROUND

Various embodiments are directed to electrosurgical cutting and sealing instruments with cam-actuated jaws that may be used, for example, in open and minimally invasive surgical environments.

Minimally invasive procedures are desirable because such procedures can reduce pain and provide relatively quick recovery times as compared to conventional open medical procedures. Many minimally invasive procedures are performed with an endoscope (including without limitation laparoscopes). Such procedures permit a physician to position, manipulate, and view medical instruments and accessories inside the patient through a small access opening in the patient's body. Laparoscopy is a term used to describe such an “endosurgical” approach using an endoscope (often a rigid laparoscope). In this type of procedure, accessory devices (such as end effectors for creating energy-induced tissue welds) are inserted into a patient through trocars placed through the body wall. Still less invasive treatments include those that are performed through insertion of an endoscope through a natural body orifice to a treatment region. Examples of this approach include, but are not limited to, cystoscopy, hysteroscopy, esophagogastroduodenoscopy, and colonoscopy.

Many of these procedures employ a flexible endoscope during the procedure. Flexible endoscopes often have a flexible, steerable articulating section near the distal end that can be controlled by the clinician by utilizing controls at the proximal end. Some flexible endoscopes are relatively small (1 mm to 3 mm in diameter), and may have no integral accessory channel (also called biopsy channels or working channels). Other flexible endoscopes, including gastroscopes and colonoscopes, have integral working channels having a diameter of about 2.0 to 3.7 mm for the purpose of introducing and removing medical devices and other accessory devices to perform diagnosis or therapy within the patient. For example, some end effectors are used to create an energy-induced weld or seal. Certain specialized endoscopes or steerable overtubes are available, such as large working channel endoscopes having a working channel of 5 mm, or larger, in diameter, which can be used to pass relatively large accessories, or to provide capability to suction large blood clots. Other specialized endoscopes include those having two or more working channels.

A common task both in minimally invasive and open surgical environments is to grasp, cut and fasten tissue while leaving the cut ends hemostatic (e.g., not bleeding). For example, it is often desirable to cut and seal bodily lumens, such as individual blood vessels or tissue including various vasculature. When sealing a fluid-carrying bodily lumen, it is often necessary for the seal to have sufficient strength to prevent leakage of the fluid, which may exert considerable fluid pressure.

Instruments exist for simultaneously making a longitudinal incision in tissue and fastening the tissue on opposing sides of the incision. Such instruments commonly include an end effector having a pair of cooperating jaw members that, if the instrument is intended for minimally invasive applications, are capable of passing through a cannula passageway or endoscopic working channel. In use, the clinician is able to close the jaw members to clamp the tissue to be cut. A reciprocating cutting instrument (or knife) is drawn distally along the jaw members to transect the clamped tissue. Simultaneously, a fastening mechanism fastens the cut ends of the tissue on opposing sides of the incision. Known fastening mechanisms include staples, sutures or various instruments utilizing energy sources. For example, various energy sources such as radio frequency (RF) sources, ultrasound sources and lasers have been developed to coagulate, seal or join together tissue volumes.

SUMMARY

Various embodiments may be directed to a surgical instrument. The surgical instrument may comprise a handle and a shaft coupled to the handle and extending distally along a longitudinal axis. An end effector may be positioned at a distal end of the shaft. According to various embodiments, the end effector may comprise a first jaw member and a second jaw member. The first jaw member may define a first longitudinal slot and may comprise a first cam track defining a first cam slot. The second jaw member may define a second longitudinal slot and may comprise a second cam track defining a second cam slot. Further, the second jaw member may be pivotable towards the first jaw member about a jaw pivot point. The end effector may also comprise a reciprocating member translatable distally and proximally parallel to the longitudinal axis through the first longitudinal slot and the second longitudinal slot. A distal portion of the reciprocating member may define a blade. Additionally, the end effector may comprise a shuttle and at least one cam pin. The shuttle may be translatable distally and proximally parallel to the longitudinal axis. The at least one cam pin may be coupled to the shuttle and may be positioned within the first cam slot and the second cam slot.

Various embodiments may also be directed to a surgical instrument comprising a handle, a shaft, an end effector and a reciprocating overtube. The shaft may be coupled to the handle and may extend distally along a longitudinal axis. The end effector may comprise a first jaw member and a second jaw member. The first jaw member may define a first longitudinal slot. The second jaw member may define a second longitudinal slot and may be pivotable towards the first jaw member about a jaw pivot point. The first jaw member and the second jaw member may be biased to an open position. A reciprocating member may be translatable distally and proximally parallel to the longitudinal axis through the first longitudinal slot and the second longitudinal slot. A distal portion of the reciprocating member may defines a blade. In some embodiments, the reciprocating member may be considered a part of the end effector. The reciprocating overtube may be translatable distally and proximally over the shaft parallel to the longitudinal axis. Distal motion of the overtube may cause the first and second jaw member to pivot towards the longitudinal axis.

FIGURES

Various features of the embodiments described herein are set forth with particularity in the appended claims. The various embodiments, however, both as to organization and methods of operation may be understood in accordance with the following description taken in conjunction with the accompanying drawings as follows.

FIG. 1 illustrates one embodiment of a transection and sealing instrument, which may be used, for example, with an endoscope.

FIG. 2 illustrates one embodiment of the transection and sealing instrument of FIG. 1 for use in electrosurgical applications.

FIGS. 3 and 4 illustrate one embodiment of an end effector of a surgical grasping instrument adapted for transecting captured tissue and contemporaneous sealing of the captured tissue with RF energy delivery.

FIGS. 5 and 6 illustrate one embodiment of the reciprocating member shown in FIGS. 3 and 4.

FIGS. 7 and 8 illustrate one embodiment of the actuation of a reciprocating member shown in FIG. 3 from a first retracted position to a second extended position to move the jaws of the end effector from an open position to a closed position.

FIG. 9 illustrates an end view of one embodiment of the reciprocating member of FIG. 3 with the jaws of the end effector in phantom view.

FIG. 10 illustrates a cross-sectional view of the embodiment shown in FIG. 9 along a cross-section taken at a position proximally located from the end view shown in FIG. 9.

FIG. 11 illustrates one embodiment of a the jaw of the end effector of FIG. 3 de-mated from the end effector.

FIGS. 12 and 13 illustrate one embodiment of an end effector comprising cam-actuated jaw members in an open position.

FIGS. 14 and 15 illustrate one embodiment of the end effector of FIGS. 12 and 13 with the jaw members in a closed position.

FIG. 16 illustrates one embodiment of the reciprocating member of the end effector of FIGS. 12 and 13.

FIG. 17 illustrates one embodiment of the reciprocating member of FIG. 16 with a shuttle and cam pin shown.

FIG. 18 illustrates one embodiment of the end effector of FIG. 12 with the clevis and the shaft shown in FIG. 12 not shown.

FIG. 19 illustrates one embodiment of the end effector as shown in FIG. 18 with the clevis also shown.

FIG. 20 illustrates one embodiment of the clevis of FIG. 12.

FIGS. 21 and 22 illustrate one embodiment of the upper jaw member of FIG. 12.

FIGS. 23 and 24 illustrate one embodiment of the lower jaw member of FIG. 12.

FIGS. 24A-24C illustrate one embodiment of an end effector comprising an overtube for providing closing force to jaw members.

FIGS. 24D and 24E illustrate one embodiment of an end effector that may be actuated with an overtube.

FIG. 25 shows an example embodiment of a vessel having opposing wall portions.

FIG. 26 is a graphic illustration of one embodiment of the opposing vessel walls portions of FIG. 25 with the tissue divided into a grid with arbitrary micron dimensions.

FIG. 27 illustrates one embodiment of the blood vessel of FIG. 25 acted upon by a device implementing a power adjustment approach to energy delivery.

FIG. 28 illustrates one embodiment of the blood vessel of FIG. 25 acted upon by a device implementing a current-path directing approach to energy delivery.

FIG. 29 illustrates one embodiment of an endoscope (illustrated here as a gastroscope) inserted into the upper gastrointestinal tract of a patient.

FIG. 30 illustrates one embodiment of a distal portion of the endoscope of FIG. 29, which may be used with the transection and sealing instrument described herein.

DESCRIPTION

Various embodiments are directed to an electrosurgical device for cutting and sealing, for example, cutting and sealing a bodily lumen. The electrosurgical device may have cam-actuated jaw members that allow a clinician to both close and open the jaw members under load. The ability to open the jaw members under load may allow the clinician to use the electrosurgical device for blunt tissue dissection (e.g., the spreading motion of the jaw members may be used to separate tissue). This may allow the clinician to minimize the total number of instruments used and the time of surgery.

FIG. 1 illustrates one embodiment of a transection and sealing instrument 100. The instrument 100 may be used with an endoscope, laparoscope, or any other suitable introduction device. According to various embodiments, the transection and sealing instrument 100 may comprise a handle assembly 102, a shaft 104 and an end effector 106. The shaft 104 may be rigid (e.g., for laparoscopic and/or open surgical application) or flexible, as shown, (e.g., for endoscopic application). In various embodiments, the shaft 104 may comprise one or more articulation points. The end effector 106 may comprise a first jaw member 108 and a second jaw member 110. The first jaw member 108 and second jaw member 110 may be connected to a clevis 112, which, in turn, may be coupled to the shaft 104. In various embodiments, as illustrated below, the jaw members 108, 110 may be directly coupled to the shaft 104 and the clevis 112 may be omitted. As illustrated in FIG. 1, the end effector 106 is shown with the jaw members 108, 110 in an open position. A reciprocating blade 118 is illustrated between the jaw members 108, 110.

According to various embodiments, one or both of the jaw members 108, 110 may include, or serve as electrodes in monopolar or bi-polar electrosurgical applications including, for example, cutting, coagulation and welding. FIG. 2 illustrates one embodiment of the transection and sealing instrument 100 for use in electrosurgical applications. The jaw members 108, 110 of the end effector 106 may comprise respective electrodes 120, 122. The electrodes 120, 122 may be connected to an electrosurgical generator 124 via wires (not shown) extending from the end effector 106 through the shaft 104 and handle 102. The generator 124 may generate any suitable type of signal for electrosurgical applications. For example, the generator 124 may make various alternating current (A/C) and/or direct current (D/C) signals at suitable voltages, currents, frequencies and wave patterns. According to various embodiments, the transection and sealing instrument 100 may be configured for monopolar operation. In this case, the end effector 106 may comprise a single electrode, rather than two. According to various embodiments, all or a portion of the end effector 106 may serve as the single electrode.

A translating member 116 may extend within the shaft 104 from the end effector 106 to the handle 102. The translating member 116 may be made from any suitable material. For example, the translating member 116 may be, a metal wire (e.g., a tri-layered steel cable), a plastic or metal shaft, etc. In some embodiments, one or more additional translating members (not shown in FIG. 2) may be included to control the motion of the end effector 106 and/or the shaft 104. In various embodiments, the instrument 100 may comprise multiple translating members 116, for example, as described below. At the handle 102, the shaft 104 may be directly or indirectly coupled to an actuator 113 (FIG. 1). In use, a clinician may cause the actuator 113 to pivot along arrow 118 from a first position to a second position. When the actuator moves from the first position to the second position, it may translate the translating member 116 distally or proximally. Distal or proximal motion of the translating member 116 may, in turn, cause the end effector 106 to transition from an open position to a closed position (or vice versa) and/or to perform various other surgical activities such as, for example, transecting and/or joining or welding. According to various embodiments, the handle 102 may comprise multiple actuators 113. When multiple actuators 113 are present, each actuator 113 may be used by a clinician to cause the end effector 106 to perform different surgical activities. In various embodiments a single actuator 113 may cause the end effector 106 to perform more than one activity. For example, a clinician may activate a single actuator 113 to force a reciprocating member 340 distally. This may, as described, both close the jaw members 108, 110 and transect any tissue between the jaw members 108, 110.

FIGS. 3 and 4 illustrate one embodiment of an end effector 106 of the instrument 100 adapted for transecting captured tissue and contemporaneous sealing of the captured tissue with RF energy delivery. The end effector 106 is carried at the distal end 304 of the shaft 104 that can be rigid, articulatable or deflectable in any suitable diameter. For example, the shaft 104 can have a diameter ranging from about 2 mm to 20 mm to cooperate with cannulae in endoscopic/laparoscopic surgeries or for use in open surgical procedures. The shaft 104 extends from a proximal handle, such as the handle 102. The handle 102 can be any type of pistol-grip or other type of handle known in the art that carries actuator levers, triggers or sliders for moving the translating member 116 or members distally and proximally to actuate the jaws as will be disclosed below. The shaft 104 has a bore 308 extending therethrough for carrying actuator mechanisms (e.g., translating member 116) for actuating the jaws and for carrying electrical leads 309 a-309 b for the electrosurgical components of the end effector 106 either simultaneously or in sequence.

FIGS. 3 and 4 show details of the end effector 106, including the (upper) jaw element 108 and (lower) jaw element 110 that are adapted to close or approximate along an axis 315. The jaw elements 108, 110 may both be moveable or a single jaw may rotate to provide the open and closed positions. In the exemplary embodiment of FIGS. 1 and 2, both the lower and upper jaws 110, 108 are moveable relative to a rolling pivot location 316 defined further below.

An opening-closing mechanism of the end effector 106 operates on the basis of cam mechanisms that provide a positive engagement of camming surfaces both distal and proximal to a pivoting location (i) for moving the jaw assembly to the (second) closed position to engage tissue under very high compressive forces, and (ii) for moving the jaws toward the (first) open position to apply substantially high opening forces for “dissecting” tissue. This feature allows the surgeon to insert the tip of the closed jaws into a dissectable tissue plane—and thereafter open the jaws to apply such dissecting forces against the tissues.

According to various embodiments, the lower and upper jaws 110, 108 may have a first end 318, in the open position, that defines first (proximally-facing) arcuate outer surface portions indicated at 320 a and 320 b that are engaged by a first surface portions 322 a and 322 b of a reciprocatable I-beam member 340 (FIG. 4) that is adapted to slide over the jaw elements 108, 110 to thereby move the jaws toward closed position. FIGS. 5 and 6 show views that illustrate the cam surfaces of reciprocating member 340 de-mated from jaws 110 and 108. The first end portion 318 of the lower and upper jaws, in the open position, further defines second (distally-facing) arcuate surface portions indicated at 330 a and 330 b that are engaged by second surface portions 332 a and 332 b (FIG. 5) of the reciprocatable member 340 for moving the jaw elements to the open position. The effective point of jaw rotation may lie between the first and second arcuate cam surfaces of the jaws. The distal (second) end region 333 of the paired jaws is rounded with a lip 334 that can serve as an electrode for surface coagulation as will be described below.

In this embodiment of FIGS. 3, 4 and 5, the reciprocating member 340 may be actuatable from the handle of the instrument by any suitable mechanism, such as actuator 113, which may be coupled to a proximal end 341 of member 340. The proximal end 341 and medial portion 341′ of member 340 are dimensioned to reciprocate within bore 308 of the shaft 104. The distal portion 342 of reciprocating member 340 carries first (lower) and second (upper) laterally-extending flanges or shoulder elements 344A and 344B that are coupled by an intermediate transverse element 345. The transverse element 345 further is adapted to transect tissue captured between the jaws with a leading edge 346 (FIG. 5) that can be a blade or a cutting electrode. The transverse element 345 is adapted to slide within channels 348 a and 348 b in the paired first and second jaws 110, 108. As can be seen best in FIGS. 5 and 6, the laterally-extending shoulder elements 344A and 344B define the surfaces 322 a, 322 b, 332 a, 332 b that slidably engage the arcuate cam surfaces of the jaws and that apply high compressive forces to the jaws in the closed position.

According to various embodiments, the first and second jaws 108 and 110 may define tissue-engaging surfaces or planes 350 a and 350 b that contact and deliver energy to engaged tissues, in part, from RF electrodes 120, 122. The engagement plane 350 a of the lower jaw 110 may be adapted to deliver energy to tissue, and the tissue-contacting surface 350 b of upper jaw 108 may be electrosurgically active or passive as will be described below. Alternatively, the engagement surfaces 350 a, 350 b of the jaws can carry any suitable electrode arrangement known in the art.

The jaws 108, 110 may have teeth or serrations 356 in any location for gripping tissue. The embodiment of FIGS. 3 and 4 depicts such serrations 356 at an inner portion of the jaws along channels 348 a and 348 b thus leaving engagement planes 350 a and 350 b laterally outward of the tissue-gripping elements. The serrations 356 may be of any suitable symmetric or asymmetric shape or combination of shapes including, for example, triangular, rounded, sinusoidal, etc. In the embodiments described below, the engagement planes 350 a and 350 b and electrode(s) 120, 122 generally are shown with a non-serrated surface for clarity of explanation, but such engagement planes and electrodes themselves can be any non-smooth gripping surface. The axial length of jaws 108, 110 indicated at L can be any suitable length depending on the anatomic structure targeted for transection and sealing. In various embodiments, the length L may be between 10 mm and 50 mm. In some embodiments, the length L may be longer. For example, one embodiment of an end effector 106 for resecting and sealing organs such as a lung or liver may have a length L of about 200 mm. Also, for example, for some surgical tasks, the jaws having a shorter length L may be used, including, for example, jaws having a length L of about 5.0 mm.

FIG. 9 illustrates an end view of one embodiment of the reciprocating member 340 with the jaws 110 and 108 in phantom view. The view shown in FIG. 9 is a head-on view with the distally positioned blade surface 346 pointed out of the page. FIG. 10 illustrates a cross-sectional view of the embodiment shown in FIG. 9 along a cross-section taken at a position proximally located from the end view shown in FIG. 9. The transverse element 345 of the reciprocating member 340 may define a transverse dimension d between innermost surfaces 358 a and 358 b of the flanges 344A, 344B of the reciprocating member 340 and cooperating medial and distal outer surfaces 360A and 360B of the jaws. The selected transverse dimension d between the flanges or shoulders 344A and 344B thus further defines the engagement gap g between the engagement planes 350 a and 350 b of the jaws in the closed position. It has been found that very high compression of tissue combined with controlled RF energy delivery is optimal for welding the engaged tissue volume contemporaneous with transection of the tissue. According to various embodiments, the engagement gap g between the engagement planes 350 a, 350 b may range from about 0.001″ to about 0.050″. For example, the gap g between the engagement planes ranges from about 0.001″ to about 0.010″. As can be seen in FIGS. 5 and 10, the medial portion 341′ of the reciprocating member 340 may have an “I”-beam shape with inner surface portions 363 a and 363 b that engage the cooperating medial outer surfaces of the jaws. Thus, in various embodiments, the entire length L of the jaws can be maintained in a fixed spaced-apart relationship to define a consistent engagement gap g. According to various embodiments, the engagement gap g may be selected to be large enough to prevent tissue engaged between the jaws 108, 110 from being sheared and to prevent electrical shorts between the electrodes 120, 122.

FIGS. 7 and 8 illustrate one embodiment of the actuation of the reciprocating member 340 from a first retracted position to a second extended position to move the jaws 110 and 108 from an open position to a closed position. Referring to FIG. 7, it can be seen that the translatable member 340 is being moved in the proximal direction so that the proximal-facing surfaces 332 a and 332 b (FIG. 5) of reciprocating member 340 about the outer surfaces 330 a and 330 b of the jaws thus forcing the jaws apart, for example to apply dissecting forces to tissues or to open jaws 108 and 110 to engage targeted tissues for hemostasis and transection. FIG. 8 shows the reciprocating member 340 after having been fully extended in the distal direction so that the distal-facing surfaces 322 a and 322 b of reciprocating member 340 have ridden up and over the proximal arcuate surfaces 320 a and 320 b of the jaws (and medial outer surfaces 360A and 360B) thus forcing the jaws together thereby producing a compressive force between jaws 108 and 110. According to various embodiments, the orientation of surfaces 322 a, 322 b of the reciprocating member 340 and/or the arcuate surfaces 320 a, 320 b may be modified to modify the compression rate provided by the reciprocating member 340. For example, the orientation of the 322 a, 322 b of the reciprocating member 340 and/or the arcuate surfaces 320 a, 320 b may vary from one embodiment to another, or may vary within a single embodiment in order to cause variable compression rates within a single stroke of the reciprocating member 340.

According to various embodiments, the jaws 108, 110 may rollably contact one another along the interface 370 between inner surfaces 372 of the first end 318 of the jaws. As jaws 108 and 110 articulate, the pivot point is moving as the point of contact changes at the interface between surfaces 370 and 372. Thus, the jaw assembly may not need to define a true single pivot point as is typical of hinge-type jaws known in the art. The pivotable action of the jaws along interface 370 may be described as a rolling pivot that optionally can allow for a degree of dynamic adjustment of the engagement gap g at the proximal end of the jaws. FIG. 11 illustrates one embodiment of a the jaw 108 de-mated from the end effector 106. Referencing FIG. 11, the jaws elements 110, 108 can be retained relative to one another and the shaft 104 by means of protruding elements 375 that couples with arcuate slots 376 in an internal member 377 that is fixedly carried in bore 308 of shaft 104. Alternatively, outwardly protruding elements can cooperate with slots in the wall of shaft 104. Also, for example, the jaw assembly may (optionally) comprise springs for urging the jaws toward the open position, or closed position depending on the desired at-rest state of the device.

FIGS. 12 and 13 illustrate one embodiment of an end effector 1200 comprising cam-actuated jaw members 1202, 1204 in an open position. The jaw members 1202, 1204 may be pivotably coupled to a clevis 1214 at a pivot point 1216 such that the jaw members 1202, 1204 may transition from the open position shown in FIGS. 12 and 13 to the closed position shown in FIGS. 14 and 15 and described below. As shown in FIGS. 12-15, both jaw members 1202, 1204 may be pivotable about the pivot point 1216. In some embodiments, however, one of the jaw members may be stationary. The pivot point 1216 may be any suitable kind of joint and, in various embodiments, may comprise a pin. The jaw members 1202, 1204 may comprise tissue-engaging surfaces or planes 1236 a, 1236 b that may be similar to the tissue engaging planes 350 a, 350 b described above and may be or comprise one or more electrodes for delivering energy to tissue held between the jaw members 1202, 1204, as described herein. Wire conduits 1242, 1244, 1246 may be present, as shown, to carry wires from the electrodes to the generator 324, e.g., via the shaft 104.

Each of the jaw members 1202, 1204 may comprise respective cam tracks 1206, 1208 positioned substantially or entirely proximally from the pivot point 1216. The cam tracks 1206, 1208 may define cam slots 1210, 1212. A shuttle 1220 may be coupled to the cam tracks 1206, 1208 via a cam pin 1218 received through both of the cam slots 1210, 1212. According to various embodiment, the cam pin 1218 may comprise two cam pins on opposite sides of the shuttle 1220. Also, according to various embodiments, the drive pin 1218 or pins may not extend all the way through the cam slots 1210, 1212.

The cam slots 1210, 1212 may be curved such that distal motion of the shuttle 1220 may cause the jaw members 1202, 1204 to pivot about the pivot point 1216 to the open position shown in FIG. 12. Similarly, proximal motion of the shuttle 1220 may cause the jaw members 1202, 1204 to pivot about the pivot point 1216 to a closed position, for example, as shown in FIGS. 14 and 15. Distal and proximal motion of the shuttle 1220 may be effected by a translating member 1230 (FIG. 17), which may extend proximally to the handle 102. At the handle 102, an actuator, such as actuator 113 may be coupled to the translating member 1230 such that a clinician may move the actuator 113 in order to cause distal and proximal motion of the translating member 1230. Distal and proximal motion of the translating member 1230 may cause similar distal and proximal motion of the shuttle 1220, which may, in turn cause the jaws 1202, 1204 to open and close.

The end effector 1200 may also comprise a reciprocating I-beam member 1224 similar to the member 340 described above. FIG. 16 illustrates one embodiment of the reciprocating member 1224. The member 1224 may comprise a transverse element 1232 and a pair of flanges 1228 a, 1228 b. The transverse element 1232 may comprise a distally directed leading edge or blade 1226, which may be sharpened or be electrically active to cut tissue. When the jaw members 1202, 1204 are in the closed position shown in FIGS. 14 and 15, the transverse element may be translated distally to cut tissue held between the jaw members 1202, 1204 and, in various embodiments, to provide a compressive force tending to hold the jaw members 1202, 1204 together. For example, the transverse element 1232 of the reciprocating member 1224 may be adapted to slide within slots 1234 a, 1234 b in the jaw members 1202, 1204. Flanges 1228 a, 1228 b may ride above the slots 1234 a, 1234 b. As the reciprocating member 1224 is translated distally through the slots 1234 a, 1234 b, the flanges 1228 a, 1228 b may exert a compressive force on the jaw members 1202, 1204, tending to force the jaw members 1202, 1204 together. The reciprocating member 1224 may be actuatable from the handle 102 of the instrument by any suitable mechanism, such as actuator 113, which may be coupled to a proximal end of member 1224. The proximal end and medial portion of member 340 may be dimensioned to reciprocate within bore 308 of the shaft 104.

According to various embodiments, the reciprocating member 1224 and the shuttle 1220 may be configured to translate distally and proximally substantially independent of one another. For example, the reciprocating member 1224 may define a slot 1236 in the transverse member 1232 for receiving the shuttle 1220 and the cam pin 1218. FIG. 17 illustrates one embodiment of the reciprocating member 1224 with the shuttle 1220 and cam pin 1218 shown. The shuttle 1220 and cam pin 1218 may be movable transversely and distally relative to the reciprocating member 1224 (e.g., as shown by arrow 1238). In this way, the reciprocating member 1224 may have a range of motion along the arrow 1238 while the shuttle 1220 is stationary. Likewise, the shuttle 1220 may have a range of motion along the arrow 1238 while the reciprocating member 1224 remains stationary.

FIG. 18 illustrates one embodiment of the end effector 1200 with the clevis 1214 and the shaft 104 shown in FIG. 12 omitted. The cam pin 1218 is shown riding within the slot 1236 in the reciprocating member 1224 as well as within the slot 1210 of the cam track 1206 of the jaw member 1202. A coupling 1240 for fastening the clevis 1214 to the shaft 104 is also illustrated. FIG. 19 illustrates one embodiment of the end effector 1200 as shown in FIG. 18 with the clevis 1214 also shown. FIG. 20 illustrates one embodiment of the clevis 1214. The clevis 1214 may comprise a pair of arms 1254, 1256. Each arm 1254, 1256 may define respective holes 1250, 1252 at the pivot point 1216, e.g., for receiving a pivot pin (not shown). As illustrated in FIG. 19, the shuttle 1220 may ride between the arms 1254, 1256. According to various embodiments, the arms 1254, 1256 may define recesses such as recess 1248 for receiving wire conduits (e.g., conduit 1242 shown in FIG. 12).

FIGS. 21 and 22 illustrate one embodiment of the jaw member 1202 of FIG. 12. As shown, the jaw member 1202 may define a hole 1260 a at about the pivot point 1216. For example, the hole 1260 a may receive a pivot pin. The perspective shown in FIG. 22 provides a view of the slot 1234 b. A surface 1262 b may partially or completely surround the slot 1234 b. The surface 1262 b may receive the flange 1228 a of the reciprocating member 1224 as it translates distally. The flange 1228 a may exert a force on the surface 1262 a, and therefore the jaw member 1202, tending to cause the jaw members 1202, 1204 to the closed position. At its proximal portion, the surface 1262 b may define an incline 1264 b for receiving the flange 1228 a. For example, the incline 1264 b may allow the flange 1228 a to engage the slot 1234 b when the jaws 1202, 1204 are not in a closed or completely closed position. FIGS. 23 and 24 illustrate one embodiment of the jaw member 1204 of FIG. 12. As illustrated, the jaw member 1204 may comprise a hole 1260 b, surface 1262 a and incline 1264 a similar to those of the jaw member 1202 described above.

Referring back to FIGS. 12 through 15, FIG. 12 shows the end effector 1200 with the jaw members 1202, 1204 in an open position. In use, the jaw members 1202, 1204 may be placed around tissue, such as a bodily lumen to be transected and sealed. When the end effector 1200 is properly positioned, the clinician may close the jaw members by actuating an actuator, such as 113, on the handle 102. This may cause the translating member 1230 to translate proximally, pulling the shuttle 1220 proximally along with the cam pin 1218. This may pull the cam pin 1218 proximally within the cam slots 1210, 1212, causing the jaw members 1202, 1204 to pivot about the pivot point 1216 to the closed position shown in FIG. 14. The clinician may then cause the reciprocating member 1224 to extend distally (e.g., by using the actuator 113 or another actuator at the handle 102). This may cause the reciprocating member 1224 to be received into the respective slots 1234 a, 1234 b. Flanges 1228 a, 1228 b may contact surfaces 1262 a, 1262 b, exerting a force on the jaw members 1202, 1204 tending to further close them, as shown in FIG. 15. The cutting edge 1226 of the reciprocating member 1224 may transect tissue held within the jaws. According to various embodiments, the reciprocating member may be extended distally before the jaw members 1202, 1204 are closed, or completely closed. For example, the flanges 1228 a, 1228 b to engage the inclines 1264 a, 1264 b, exerting a force on the jaw members 1202, 1204 tending to close them. In various embodiments, transected tissue within the jaws 1202, 1204 may be sealed, for example, utilizing the electrical energy techniques described herein. To open the jaw members 1202, 1204, the reciprocating member 1224 may be withdrawn proximally from the slots 1234 a, 1234 b. The shuttle 1220 may be pushed distally, for example, by exerting a distally directed force on the translating member 1230 (e.g., via the handle 102). Distal motion of the shuttle 1220 may cause the cam pin 1216 to slide distally within the cam slots 1210, 1212. This may, in turn force the jaw members 1202, 1204 to the open position. In various surgical situations, this may allow the clinician to dissect or separate tissue with the instrument 100. Allowing the clinician to transect and seal as well as dissect with the same instrument 100 may minimize the number of instrument changes required during an operation, thus reducing time and potentially cost.

FIGS. 24A-24C illustrate one embodiment of an end effector 2500′ comprising an overtube 3802 for providing closing force to jaw members 2502, 2504. As illustrated in FIGS. 12-13 and 24A-24C, the respective cam portions 2508, 2510 of the jaw members 2502, 2504 may protrude away from a longitudinal axis 3806 of the end effector 2500′. As the jaw members 2502, 2504 are closed, as shown in FIGS. 12-15, the cam portions 2508, 2510 translate towards the axis 3806. According to various embodiments, additional clamping force between the jaw members 2502, 2504 may be obtained by forcing the cam portions 2508, 2510 towards the axis 3806. This may be performed by an overtube 3802. The overtube 3802, like the reciprocating member 2524 and shuttle 2520 may be translatable distally and proximally by the clinician from the handle 102. To close the jaw members 2502, 2504, the shuttle 2520 may be translated proximally, causing the jaw members 2502, 2504 to pivot towards the axis 3806, as illustrated and described with reference to FIGS. 14-15. Overtube 3802 may then be translated distally, where it may contact the cam portions 2508, 2506, tending to force them and their respective jaw members 2502, 2504 towards the longitudinal axis 3806. This may provide additional clamping force tending to force the jaw members 2502, 2504 together towards the longitudinal axis 3806. In some embodiments, the overtube 3802 may be shortened in length to more closely resemble a ring for applications involving flexible shafts. This would be of particular benefit for use in flexible endoscopic applications.

According to various embodiments, the shapes of the cam portions 2506 and 2508 and/or the overtube 3802 may be optimized to reduce the force necessary to force the overtube 3802 distally and/or to increase the compression force put on the jaw members 2502, 2504. For example, the cam portions 2506, 2508 may have curved sections 3810, 3812 positioned to contact the overtube 3802. The curved portions may be shaped to act as a camming surface to guide the overtube 3802 over the cam portions 2506, 2508 and progressively increase the compressive force provided by the overtube 3802 as it is translated distally. In some embodiments, the overtube 3802 may also comprise beveled camming surfaces 3808 around its interior distal edge to also guide the overtube 3802 over the cam portions 2506, 2508 and progressively increase the compressive force provided by the overtube 3802 as it is translated distally. Also, according to various embodiments, it will be appreciated that the end effector 2500′ may utilize a reciprocating member 2524 with flanges 2528 a, 2528 b, as illustrated in FIGS. 16-18. The flanges 2528 a, 2528 b may serve, as described, to provide additional compressive force as the reciprocating member 2524 is translated distally. In other various embodiments, a reciprocating member 2520 may be used, as shown in FIG. 24C. The reciprocating member 2520 may comprise a sharp leading edge for severing tissue, and may traverse within slots 2534 a, 2534 b of the respective jaw member 2502, 2504. The member 2520, however, may lack flange members, such as 2528 a, 2528 b. Accordingly, embodiments comprising a reciprocating member such as the member 2520 may rely on the cam portions 2508, 2506, cam slots 2512, 2510, and overtube 3802 to close the jaw members 2502, 2504 and provide compressive force.

FIGS. 24D and 24E illustrate one embodiment of an end effector 2499 that may be actuated with an overtube 2456. Jaw members 2452, 2454 may be actuatable from an open position shown in FIG. 24D to a closed position shown in FIG. 24E. The jaw members 2452, 2454 may be pivotably coupled to a clevis 2450 by a pin or other suitable connector at pivot point 2460. A spring 2462, or other suitable device, may mechanically bias the jaw members 2452, 2454 to the open position. The clevis 2450 may be coupled to a shaft 2464 extending proximally to the handle (not shown). According to various embodiments, the clevis 2450 may be an integral component of the shaft 2464. The overtube 2456 may also extend proximally to the handle (not shown) and may be translatable proximally and distally over the shaft 2464. According to various embodiments, a clinician may close the jaw members 2452, 2454 by translating the overtube 2456 distally (e.g., using an actuator such as 113 or other suitable mechanism). As the overtube 2456 translates distally, it may contact the jaw members 2452, overcome the mechanical biasing provided by the spring 2462 and rotate the jaw members about the pivot point 2460 towards the longitudinal axis 3806, as shown in FIG. 24E. While the jaw members 2454, 2452 are in the closed position, a reciprocating member 2458 having a blade tip 2466 may be extended distally to sever any tissue present between the jaw members 2452, 2454. It will be appreciated that motion of the reciprocating member 2458 may be in conjunction with or independent of the motion of the overtube 2456. To open the jaw members 2452, 2454, the overtube 2456 may be retracted proximally, allowing the spring 2462 to re-bias the jaw members 2452, 2454 to the open position shown in FIG. 24D.

According to various embodiments, the end effectors 106 and 1200 may be used to cut and fasten tissue utilizing electrical energy. The examples described below are illustrated with the end effector 106. It will be appreciated, however, that similar configurations and techniques may be used with the end effector 1200 described above. Referring to the end effector 106 shown in FIGS. 3-4 and 7-8, the electrodes 120, 122 of the end effector 106 may be arranged in any suitable configuration. In use, for example, tissue (not shown) may be captured between the jaw members 108, 110. RF current may flow across the captured tissue between the opposing polarity electrodes 120, 122. This may serve to join the tissue by coagulation, welding, etc. The RF current may be activated according to any suitable control method. For example, according to various embodiments, the electrodes 120, 122 may be used to implement a “power adjustment” approach, a “current-path directing” approach or an approach referred to herein as a “weld” or “fusion” approach. These various approaches are illustrated herein with reference to FIGS. 25-28, which show the walls of an example blood vessel acted upon by various RF end effectors including those using the power adjustment and current-path directing approaches from above.

FIG. 25 shows an example embodiment of a vessel having opposing wall portions 2 a and 2 b. FIG. 26 is a graphic illustration of one embodiment of the opposing vessel walls portions 2 a and 2 b with the tissue divided into a grid with arbitrary micron dimensions. For example, the grid may represent 5 microns on each side of the targeted tissue. In order to coagulate or weld tissue, collagen and other protein molecules within an engaged tissue volume may be denatured by breaking the inter- and intra-molecular hydrogen bonds. When heat or other energy is removed (e.g., thermal relaxation), the molecules are re-crosslinked to create a fused-together tissue mass. It is desirable that each micron-dimensioned volume of tissue be elevated to the temperature needed to denature the proteins therein in a substantially uniform manner.

Failing to heat tissue portions in a uniform manner can lead to ohmic heating, which can create portions of tissue that are not effectively joined and reduce the strength of the joint. Non-uniformly denatured tissue volume may still be “coagulated” and can prevent blood flow in small vasculature that contains little pressure. However, such non-uniformly denatured tissue may not create a seal with significant strength, for example in 2 mm to 10 mm arteries that contain high pressures. It is often difficult to achieve substantially uniform heating with a bipolar RF device in tissue, whether the tissue is thin or thick. For example, as RF energy density in tissue increases, the tissue surface tends to become desiccated and resistant to additional ohmic heating. Localized tissue desiccation and charring can sometimes occur almost instantly as tissue impedance rises, which then can result in a non-uniform seal in the tissue. Also, many RF jaws cause further undesirable effects by propagating RF density laterally from the engaged tissue thus causing unwanted collateral thermal damage.

To achieve substantially uniform coagulation, various embodiments described herein may utilize a “power adjustment” approach, a “current-path directing” approach and/or an approach referred to herein as a “weld” or “fusion” approach. According to the “power adjustment” approach, the RF generator 124 can rapidly adjust the level of total power delivered to the jaws' engagement surfaces in response to feedback circuitry, which may be present within the generator 124 and/or at the end effector 106, and may be electrically coupled to the active electrodes. The feedback circuitry may measure tissue impedance or electrode temperature. For example, temperature probes present on the jaw members 109, 110, 1202, 1204 may be in communication with the generator 123 and may sense electrode temperature. FIG. 27 illustrates one embodiment of the blood vessel of FIG. 25 acted upon by a device implementing a “power adjustment” approach to energy delivery. Opposing vessel walls 2 a and 2 b are shown compressed with cut-away phantom views of opposing polarity electrodes 2702, 2704 on either side of the tissue. For example, the electrode 2702 may be positioned on one jaw member 108, 110, while the electrode 2704 may be positioned on the opposite jaw member. One advantage of such an electrode arrangement is that 100% of each jaw engagement surface comprises an “active” conductor of electrical current—thus no tissue is engaged by an insulator which theoretically would cause a dead spot (no ohmic heating) proximate to the insulator.

FIG. 27 also graphically depicts current paths p in the tissue at an arbitrary time interval that can be microseconds (μs) apart. Such current paths p would be random and constantly in flux—along transient most conductive pathways through the tissue between the opposing polarity electrodes. The thickness of the paths is intended to represent the constantly adjusting power levels. Typically, the duration of energy density along any current path p is on the order of microseconds and the thermal relaxation time of tissue is on the order of milliseconds. Instruments using the power adjustment approach may be useful for sealing relatively small vessels with relatively low fluid pressure. This is because, given the spatial distribution of the current paths and the dynamic adjustment of their power levels, it is unlikely that enough random current paths will revisit and maintain each discrete micron-scale tissue volume at the targeted temperature before thermal relaxation. Also, because the hydration of tissue is constantly reduced during ohmic heating—any region of more desiccated tissue will lose its ohmic heating, rendering it unable to be “welded” to adjacent tissue volumes.

In a second “current-path directing” approach, the end effector jaws carry an electrode arrangement in which opposing polarity electrodes are spaced apart by an insulator material, which may cause current to flow within an extended path through captured tissue rather than simply between surfaces of the first and second jaws. For example, electrode configurations similar to those shown below in FIG. 28 may be implemented on tissue engaging surfaces 350 a, 350 b, 1236 a, 1236 b.

“Current-path directing” techniques are also used to improve the quality of energy-delivered seals. FIG. 28 illustrates one embodiment of the blood vessel of FIG. 25 acted upon by a device implementing a current-path directing approach to energy delivery. In FIG. 28, vessel walls 2 a and 2 b are engaged between opposing jaws surfaces with cut-away phantom views of electrodes 2802, 2804, 2806, 2808, with opposing polarity (+) and (−) electrodes (2802, 2804 and 2806, 2808) on each side of the engaged tissue. For example, electrodes 2802 and 2804 may be positioned on one of the jaw members 108, 110, 1202, 1204 while electrodes 2806 and 2808 may be positioned on the opposite jaw member. An insulator 2810 is shown in cut-away view that electrically isolates the electrodes in the jaw. The tissue that directly contacts the insulator 2810 will only be ohmically heated when a current path p extends through the tissue between the spaced apart electrodes. FIG. 28 graphically depicts current paths p at any arbitrary time interval, for example in the μs range. Again, such current paths p will be random and in constant flux along transient conductive pathways.

A third approach, according to various embodiments, may be referred to as a “weld” or “fusion” approach. The alternative terms of tissue “welding” and tissue “fusion” are used interchangeably herein to describe thermal treatments of a targeted tissue volume that result in a substantially uniform fused-together tissue mass, for example in welding blood vessels that exhibit substantial burst strength immediately post-treatment. Such welds may be used in various surgical applications including, for example, (i) permanently sealing blood vessels in vessel transection procedures; (ii) welding organ margins in resection procedures; (iii) welding other anatomic ducts or lumens where permanent closure is desired; and also (iv) for performing vessel anastomosis, vessel closure or other procedures that join together anatomic structures or portions thereof.

The welding or fusion of tissue as disclosed herein may be distinguished from “coagulation”, “hemostasis” and other similar descriptive terms that generally relate to the collapse and occlusion of blood flow within small blood vessels or vascularized tissue. For example, any surface application of thermal energy can cause coagulation or hemostasis—but does not fall into the category of “welding” as the term is used herein. Such surface coagulation does not create a weld that provides any substantial strength in the treated tissue.

A “weld,” for example, may result from the thermally-induced denaturation of collagen and other protein molecules in a targeted tissue volume to create a transient liquid or gel-like proteinaceous amalgam. A selected energy density may be provided in the targeted tissue to cause hydrothermal breakdown of intra- and intermolecular hydrogen crosslinks in collagen and other proteins. The denatured amalgam is maintained at a selected level of hydration—without desiccation—for a selected time interval, which may be very brief. The targeted tissue volume may be maintained under a selected very high level of mechanical compression to insure that the unwound strands of the denatured proteins are in close proximity to allow their intertwining and entanglement. Upon thermal relaxation, the intermixed amalgam results in protein entanglement as re-crosslinking or renaturation occurs to thereby cause a uniform fused-together mass.

To implement the welding described above, the electrodes 120, 122 (or electrodes that are part of the other end effector embodiments described herein) may, one or both, comprise an electrically conductive portion, such as copper or another suitable metal or alloy, and a portion comprising a positive temperature coefficient (PTC) material having a selected increased resistance that differs at selected increased temperatures thereof. The PTC material may be positioned between the electrically conductive portion and any tissue to be acted upon by the end effector 106. One type of PTC material is a ceramic that can be engineered to exhibit a selected positively slope curve of temperature-resistance over a temperature range of about 37° C. to 100° C. Another type of PCT material may comprise a polymer having similar properties. The region at the higher end of such a temperature range brackets a targeted “thermal treatment range” at which tissue can be effectively welded. The selected resistance of the PTC matrix at the upper end of the temperature range may substantially terminate current flow therethrough.

In operation, it can be understood that the electrodes 120 or 122 will apply active RF energy (ohmic heating within) to the engaged tissue until the point in time that the PTC matrix is heated to exceed the maximum of the thermal treatment range. Thereafter, RF current flow from the engagement surface will be lessened—depending on the relative surface areas of the first and second electrodes 120, 122. This instant and automatic reduction of RF energy application may prevent any substantial dehydration of tissue proximate to the engagement plane. By thus maintaining an optimal level of moisture around the engagement plane, the working end can more effectively apply energy to the tissue—and provide a weld thicker tissues with limited collateral thermal effects.

In various embodiments, surgical instruments utilizing various embodiments of the transection and sealing instrument 100, with the various end effectors and actuating mechanisms described herein may be employed in conjunction with a flexible endoscope. FIG. 29 illustrates one embodiment of an endoscope 2914 (illustrated here as a gastroscope) inserted into the upper gastrointestinal tract of a patient. The endoscope 2914 may be any suitable endoscope including, for example, the GIF-100 model available from Olympus Corporation. The endoscope 2914 has a distal end 2916 that may include various optical channels, illumination channels, and working channels. According to various embodiments, the endoscope 2914 may be a flexible endoscope.

FIG. 30 illustrates one embodiment of a distal portion 2916 of the endoscope 2914, which may be used with the transection and sealing instrument 100 described herein. The example endoscope 2914 shown comprises a distal face 294, which defines the distal ends of illumination channels 298, an optical channel 2906 and a working channel 2910. The illumination channels 2908 may comprise one or more optical fibers or other suitable waveguides for directing light from a proximally positioned light source (not shown) to the surgical site. The optical channel 2906 may comprise one or more optical fibers or other suitable waveguides for receiving and transmitting an image of the surgical site proximally to a position where the image may be viewed by the clinician operating the endoscope 2914. As described above, the working channel 2910 may allow the clinician to introduce one or more surgical tools to the surgical site. Examples of such surgical tools include scissors, cautery knives, suturing devices, and dissectors. It will be appreciated that the endoscope 2914 is but one example of an endoscope that may be used in accordance with various embodiments. Endoscopes having alternate configurations of optical channels 2906, illumination channels 2908 and/or working channels 2910 may also be used. According to various embodiments, the endoscope 2914 may be, or may be used in conjunction with, steerable devices such as traditional flexible endoscopes or steerable overtubes as described in U.S. Patent Application Publication No. 2010/0010299, incorporated herein by reference. Combinations of flexible endoscopes and steerable overtubes may also be used in some embodiments.

In at least one such embodiment, the endoscope 2914, a laparoscope, or a thoracoscope, for example, may be introduced into the patient trans-anally through the colon, the abdomen via an incision or keyhole and a trocar, or trans-orally through the esophagus or trans-vaginally through the cervix, for example. These devices may assist the clinician to guide and position the transection and sealing instrument 100 near the tissue treatment region to treat diseased tissue on organs such as the liver, for example.

In one embodiment, Natural Orifice Translumenal Endoscopic Surgery (NOTES)™ techniques may be employed to introduce the endoscope 2914 and various instruments into the patient and carry out the various procedures described herein. A NOTES™ technique is a minimally invasive therapeutic procedure that may be employed to treat diseased tissue or perform other therapeutic operations through a natural opening of the patient without making incisions in the abdomen. A natural opening may be the mouth, anus, and/or vagina. Medical implantable instruments may be introduced into the patient to the target area via the natural opening. In a NOTE™ technique, a clinician inserts a flexible endoscope into one or more natural openings of the patient to view the target area, for example, using a camera. During endoscopic surgery, the clinician inserts surgical devices through one or more lumens or working channels of the endoscope 2914 to perform various key surgical activities (KSA). These KSAs include forming an anastomosis between organs, performing dissections, repairing ulcers and other wounds. Although the devices and methods described herein may be used with NOTES™ techniques, it will be appreciated that they may also be used with other surgical techniques including, for example, other endoscopic techniques, and laparoscopic techniques.

It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician manipulating an end of an instrument extending from the clinician to a surgical site (e.g., through a trocar, through a natural orifice or through an open surgical site). The term “proximal” refers to the portion closest to the clinician, and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

While several embodiments have been illustrated and described, and while several illustrative embodiments have been described in considerable detail, the described embodiments are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. Those of ordinary skill in the art will readily appreciate the different advantages provided by these various embodiments.

While several embodiments have been described, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the embodiments. For example, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The described embodiments are therefore intended to cover all such modifications, alterations and adaptations without departing from the scope of the appended claims.

Various embodiments are directed to apparatuses, systems, and methods for the treatment of tissue. Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. It will be understood by those skilled in the art, however, that the embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. Those of ordinary skill in the art will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and illustrative. Variations and changes thereto may be made without departing from the scope of the claims.

Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation.

The entire disclosures of the following non-provisional United States patents are hereby incorporated by reference herein:

-   U.S. Pat. No. 7,381,209, entitled ELECTROSURGICAL INSTRUMENT; -   U.S. Pat. No. 7,354,440, entitled ELECTROSURGICAL INSTRUMENT AND     METHOD OF USE; -   U.S. Pat. No. 7,311,709, entitled ELECTROSURGICAL INSTRUMENT AND     METHOD OF USE; -   U.S. Pat. No. 7,309,849, entitled POLYMER COMPOSITIONS EXHIBITING A     PTC PROPERTY AND METHODS OF FABRICATION; -   U.S. Pat. No. 7,220,951, entitled SURGICAL SEALING SURFACES AND     METHODS OF USE; -   U.S. Pat. No. 7,189,233, entitled ELECTROSURGICAL INSTRUMENT; -   U.S. Pat. No. 7,186,253, entitled ELECTROSURGICAL JAW STRUCTURE FOR     CONTROLLED ENERGY DELIVERY; -   U.S. Pat. No. 7,169,146, entitled ELECTROSURGICAL PROBE AND METHOD     OF USE; -   U.S. Pat. No. 7,125,409, entitled ELECTROSURGICAL WORKING END FOR     CONTROLLED ENERGY DELIVERY; -   U.S. Pat. No. 7,112,201, entitled ELECTROSURGICAL INSTRUMENT AND     METHOD OF USE; -   U.S. Patent Application Publication No. 2010/0010299, entitled     ENDOSCOPIC TRANSLUMENAL ARTICULATABLE STEERABLE OVERTUBE; and -   U.S. Patent Application Publication No. 2006/0111735, entitled     CLOSING ASSEMBLIES FOR CLAMPING DEVICE.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

The devices disclosed herein may be designed to be disposed of after a single use, or they may be designed to be used multiple times. In either case, however, the device may be reconditioned for reuse after at least one use. Reconditioning may include a combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device may be disassembled, and any number of particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device may be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those of ordinary skill in the art will appreciate that the reconditioning of a device may utilize a variety of different techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of this application.

Preferably, the embodiments described herein will be processed before surgery. First a new or used instrument is obtained and, if necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK® bag. The container and instrument are then placed in a field of radiation that may penetrate the container, such as gamma radiation, x-rays, or higher energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

The embodiments are not to be construed as limited to the particular embodiments disclosed. The embodiments are therefore to be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the claims. Accordingly, it is expressly intended that all such equivalents, variations and changes that fall within the scope of the claims be embraced thereby.

In summary, numerous benefits have been described which result from employing the embodiments described herein. The foregoing description of the one or more embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments were chosen and described in order to illustrate principles and practical applications to thereby enable one of ordinary skill in the art to utilize the various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope. 

What is claimed is:
 1. A surgical instrument comprising: a handle; a shaft coupled to the handle and extending distally along a longitudinal axis; an end effector positioned at a distal end of the shaft, wherein the end effector comprises: a first jaw member defining a first longitudinal slot, wherein the first jaw member comprises a first cam track defining a first cam slot; and a second jaw member defining a second longitudinal slot, wherein the second jaw member is pivotable towards the first jaw member about a jaw pivot point, and wherein the second jaw member comprises a second cam track defining a second cam slot; a reciprocating member translatable distally and proximally parallel to the longitudinal axis through the first longitudinal slot and the second longitudinal slot, wherein a distal portion of the reciprocating member defines a blade; a shuttle translatable distally and proximally parallel to the longitudinal axis, wherein the reciprocating member defines at least one slot and wherein the shuttle is positioned to translate within the slot distally and proximally relative to the reciprocating member; and at least one cam pin coupled to the shuttle and positioned within the first cam slot and the second cam slot.
 2. The surgical instrument of claim 1, wherein the first jaw member is pivotable towards the second jaw member about the jaw pivot point.
 3. The surgical instrument of claim 1, wherein the reciprocating member comprises a pair of flanges positioned to ride above the first and second longitudinal slots when the reciprocating member is extended distally through the first and second longitudinal slots.
 4. The surgical instrument of claim 1, wherein the at least one cam pin comprises a single cam pin positioned to extend through the shuttle, the first cam slot and the second cam slot.
 5. The surgical instrument of claim 1, wherein the first jaw member further comprises a first electrode and the second jaw member further comprises a second electrode.
 6. The surgical instrument of claim 5, wherein at least one of the first electrode and the second electrode comprises a first electrically conductive portion and a positive temperature coefficient (PTC) portion.
 7. The surgical instrument of claim 6, wherein the PTC portion comprises at least one material selected from the group consisting of a polymer PTC material and a ceramic PTC material.
 8. The surgical instrument of claim 5, wherein the PTC portion comprises a PTC material with a temperature dependent electrical resistance such that the electrical resistance of the PTC material increases to substantially eliminate current flowing through the PCT material at a predetermined temperature.
 9. The surgical instrument of claim 5, further comprising an electrosurgical generator in electrical communication with the first and second electrodes.
 10. The surgical instrument of claim 9, wherein the electrosurgical generator comprises feedback circuitry configured to modify power delivered to the first and second electrode based on at least one property of the electrode selected from the group consisting of tissue impedance and electrode temperature.
 11. The surgical instrument of claim 1, wherein the first jaw member comprises a tissue engagement surface comprising a positive electrode and a negative electrode separated by an insulator.
 12. The surgical instrument of claim 1, further comprising a first translating member coupled to the shuttle and extending proximally from the shuttle through the shaft to the handle.
 13. The surgical instrument of claim 1, wherein the reciprocating member extends proximally from through the shaft to the handle.
 14. The surgical instrument of claim 1, wherein the end effector further comprises a clevis comprising a first arm and a second arm, wherein the first arm and the second arm define holes positioned at about the pivot point.
 15. The surgical instrument of claim 1, wherein the reciprocating member extends proximally through the shaft to the handle.
 16. A method of using the surgical instrument of claim 1, the method comprising: translating the shuttle and cam pin proximally to cause the first and second jaw members to close; and translating the reciprocating member distally through the longitudinal slots.
 17. The method of claim 16, wherein the translating of the shuttle occurs prior to the translating of the reciprocating member.
 18. The method of claim 16, further comprising: translating the reciprocating member proximally; and translating the shuttle and cam pin distally to cause the first and second jaw members to open.
 19. A surgical instrument comprising: an end effector comprising: a first jaw member defining a first longitudinal slot, wherein the first jaw member comprises a first cam track defining a first cam slot; and a second jaw member defining a second longitudinal slot, wherein the second jaw member is pivotable towards the first jaw member about a jaw pivot point, and wherein the second jaw member comprises a second cam track defining a second cam slot; a reciprocating member translatable distally and proximally parallel to the longitudinal axis through the first longitudinal slot and the second longitudinal slot, wherein a distal portion of the reciprocating member defines a blade; a shuttle translatable distally and proximally parallel to the longitudinal axis, wherein the reciprocating member defines at least one slot and wherein the shuttle is positioned to translate within the slot distally and proximally relative to the reciprocating member; and at least one cam pin coupled to the shuttle and positioned within the first cam slot and the second cam slot; and a shaft extending proximally from the end effector. 